{"ID":23474940,"CreatedAt":"2026-09-18T01:09:05.407443952Z","UpdatedAt":"2026-09-20T18:11:56.143995915Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2609.19553","arxiv_id":"2609.19553","title":"From Parameters to Behaviors: A Survey of Model Fusion for Large Language Models","abstract":"Model fusion integrates the capabilities from source models into a single target model. As of June 2026, Hugging Face hosts more than 2M models. This growing pool provides a rich base for model reuse and capability integration. Yet existing surveys often cover only separate parts of this space, and they do not provide a unified definition or a systematic taxonomy. This survey defines model fusion and organizes prior work into three levels: parameter-level, representation-level, and behavior-level fusion. We also review related metrics, benchmarks, and applications, summarize current challenges, and identify future directions. Our goal is to provide a clear map of this area and support future work on model fusion. A comprehensive list of papers about model fusion is available at https://github.com/Baicaihaochi/Awesome-Model-Fusion-Survey.","short_abstract":"Model fusion integrates the capabilities from source models into a single target model. As of June 2026, Hugging Face hosts more than 2M models. This growing pool provides a rich base for model reuse and capability integration. Yet existing surveys often cover only separate parts of this space, and they do not provide...","url_abs":"https://arxiv.org/abs/2609.19553","url_pdf":"https://arxiv.org/pdf/2609.19553v1","authors":"[\"Shuo Cai\",\"Yanggan Gu\",\"Zihao Wang\",\"Yuanyi Wang\",\"Yibo Yan\",\"Wenjun Wang\",\"Yuhang Liu\",\"Guanghao Zhu\",\"Sirui Huang\",\"Ming Li\",\"Hongxia Yang\"]","published":"2026-09-17T01:24:23Z","proceeding":"cs.CL","tasks":"[\"cs.CL\"]","methods":"[\"Language Model\",\"Generative Adversarial Network\"]","has_code":false,"code_links":[{"ID":639783,"CreatedAt":"2026-09-18T01:09:05.407443952Z","UpdatedAt":"2026-09-18T01:09:05.407443952Z","DeletedAt":null,"paper_id":23474940,"paper_url":"https://arxiv.org/abs/2609.19553","paper_title":"From Parameters to Behaviors: A Survey of Model Fusion for Large Language Models","repo_url":"https://github.com/Baicaihaochi/Awesome-Model-Fusion-Survey","is_official":false,"mentioned_in_paper":false,"mentioned_in_github":true,"github_stars":0}]}